Improving the corrosion resistance of 7055 alloy by manipulating passivation film through trace addition of TiB2 nanoparticles

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Authors

  • Xuekai Li
  • Wei Wang
  • Yihong Wu
  • Huijun Kang
  • Enyu Guo
  • Zongning Chen
  • Yanjin Xu
  • Tongmin Wang

Organisational units

External Organisational units

  • Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province)
  • AVIC Manufacturing Technology Institute

Abstract

In this study, 7055 alloy inoculated by a minor addition of TiB 2 nanoparticles was prepared and subjected to passivation treatment. The microstructures, pitting behaviors, and electrochemical properties of the 7055-0.5TiB 2 composite were comparatively investigated with respect to the base alloy. The results show that the incorporation of 0.5 wt% TiB 2 nanoparticles refines the grain size (from 142.4 μm to 44.1 μm) and reduces the volume fractions of the residual intermediates from 0.59 % to 0.49 %, leading to an increased thickness (from 4.05 nm to 5.95 nm) and improved homogeneity of the passivation film. Both the pitting diameter and the pitting area fractions are reduced upon immersing in 3.5 % NaCl for 24 h. Electrochemical test results show that the values of passivation layer resistance, charge transfer resistance, and polarization resistance are significantly increased, while the corrosion current is reduced after the incorporation of TiB 2 nanoparticles, confirming the formation of a more effective barrier layer, i.e., the passivation film. The improved corrosion resistance of 7055 alloy with the incorporation of TiB 2 nanoparticles is attributed to the reduced active dissolution rate in the grain boundary region and a more uniform and thicker passivation film with a lower corrosion rate.

Details

Original languageEnglish
Article number159722
JournalApplied surface science
Volume656.2024
Issue number30 May
Early online date16 Feb 2024
DOIs
Publication statusPublished - 30 May 2024